1. Field
Apparatuses and methods consistent with exemplary embodiments relate to apparatuses for and methods of recording holograms, and more particularly, to apparatuses for and methods of recording holograms at high speed by simultaneously recording a plurality of hogels.
2. Description of the Related Art
Hologram technology is used for reproducing a signal as a three-dimensional (3D) image by recording interference fringes between a signal beam carrying the signal and a reference beam. Such hologram technology may be variously used for recording and reproducing 3D images, preventing forging of and identifying genuine goods, and recording and reproducing digital data. Also, this technology may be used to record fine interference fringes on a photosensitive recording film of a flat plate type in a pixel (or hologram pixel, i.e., hogel) unit so as to allow a user to see 3D images on a two-dimensional (2D) plane.
Holograms may be classified into rear projective holograms and reflective holograms. A rear projective hologram is one where light transmitting through a recording film carries 3D images, and a reflective hologram is one where light reflected from a recording film carries 3D images. In particular, the reflective hologram may be used to record/reproduce frill-color and full-parallax images, and may represent gray scales.
A hologram may be generally recorded by splitting a beam emitted from a light source into a signal beam and a reference beam, optically modulating the signal beam, and irradiating the signal beam and the reference beam to the same location on a photosensitive recording film. The modulation of the signal beam may be performed by, for example, a spatial optical modulator according to an interference pattern that is calculated by a computer based on an image that will be finally reproduced from the photosensitive recording film.
For high speed hologram recording, it is very important to simultaneously record hogels that are basic units of the hologram. In general, a plurality of optical elements may be provided to overlap with each other to record the hogels at the same time. However, this may increase the costs for manufacturing a hologram recording apparatus, and there may be a spatial limitation in installing the hologram recording apparatus.